I just wanted to pass along a technique I've been using that I haven't ever really heard anyone mention or talk about. I have to align my projector sometimes several times for a drawing and we all know it helps that the image lines up perfectly each time. It can be time consuming and fusterating.

A friend of mine passed along this info as he used to be a silk screener for a living. He said 'why don't you use four crop marks at each corner like I used to do for silk screening so it's perfect every time?'. So that's what I do now and it's been very useful.

I hand made the crop marks in Adobe Photoshop CC and create a white boarder around the whole drawing placing the crop marks at each corner so it's nice and visible. Then when I project the drawing, I also mark the crop marks.